Solar street lights don’t need to be connected to the grid, but site preparation is still required. The site conditions will have a direct bearing on the amount of solar energy generated, the lighting performance, and the long-term operation of the project in all cases (roads, parks, car parks, and other public spaces).

Without proper pre-installation checks, the solar street lights you’ve specified may end up with insufficient charging, poor light levels, or maintenance problems. Several issues need to be addressed before installation.

1. Check the Sunlight Conditions

Solar street lights use solar panels to absorb sunlight and charge the battery. Sunlight at the site of installation is therefore a very important factor.

Check that the solar panels aren’t in the shadow of any nearby buildings, trees or other structures. This is particularly relevant in urban areas where there may be limited direct sun.

Look at the seasonality. In areas with shorter daylight hours and/or more overcast weather, you may well need to increase the solar panel and battery capacity to meet the lighting demand.

Assessing the local solar resource (i.e., the amount of sunlight) is key to determining the appropriate solar panel design and system configuration.

2. Evaluate the Installation Location

The site of installation has an effect on the amount of solar energy generated, the lighting coverage, and future maintenance.

For road works, check that the proposed pole positions are acceptable and not blocked by trees, signs, buildings, or other features. You’ll also need to consider the road width, where the sidewalk is to be placed, and the flow of traffic.

In the case of limited space, make sure there is adequate clearance around the pole for installation. Check that the dimensions and mounting of the various solar panel structures are compatible with the site.

3. Confirm the Lighting Requirements

Lamp wattage by itself doesn't dictate the lighting performance of a solar street light.

Lighting requirements will vary by road and by application. Main roads will require a wider coverage and more uniform lighting, whereas residential roads, parks and parking lots will have lighting layouts specific to their particular application.

Before you go any further, check the road width, pole height, light spacing, and the required illuminance. If in doubt, use lighting simulations to check the distribution and ensure there are no dark spots or uneven lighting.

4. Check the Ground and Foundation Conditions

A good solid base is absolutely essential for the structural integrity of the solar street light pole.

Before you go any further, assess the ground type, the soil conditions and any underground pipework or other facilities. The requirements for the foundation will be different depending on whether you're installing on concrete, asphalt or soil.

Foundation design must take into account pole height, luminaire weight and local wind loads. Particular attention must be paid to the stability of the pole and foundation in coastal, open or windy areas.

Checking that these conditions are met in advance will help to minimise the amount of installation adjustment required and hence the amount of rework.

5. Consider Battery Capacity and Lighting Duration

The battery will store the electricity generated during the day for use at night. Prior to installation you need to establish what your daily lighting requirement is and whether you require the system to be capable of running through a period of consecutive overcast or rainy days.

Local sunlight, lamp power and lighting hours all have an effect on the battery capacity that you'll need. If you're looking at providing all night lighting or operation following several days of bad weather then your solar panel and battery configuration has to be properly matched.

Also confirm that the controller supports the required dimming modes and operating schedules so that the system can distribute the stored energy in accordance with actual lighting requirements.

6. Plan for Future Maintenance

Solar street lights still need to be inspected and maintained. You need to plan for the maintenance requirements in advance if you’re going to have a smooth long-term operation. The battery and the controller can be accessed for inspection and/or replacement. Adequate working space around the pole should also be considered.

In dusty areas, areas with coastal salt spray, or areas that get seasonal snow, you’ll need to consider the structure of the solar panels as well as the cleaning requirements. Choose the right products for the local conditions to minimize long-term maintenance.

Conclusion

Before you go ahead and install solar street lights, you need to assess the sunlight conditions, the installation locations, the lighting requirements, the ground and foundation conditions, the battery configuration, and the maintenance requirements. If you overlook any of these, it could affect the project’s performance.

Solar street light design and configuration should be appropriate to the type of road and the application environment. SUNFREE has solar street lights and vertical solar tubes, and can provide a bespoke solution depending on the project. They can help the customer to pick the right solar lighting system.